The study was aimed to observe the changes of blood coagulation factors in the SD rats suffered from hemorrhagic shock, and to investigate the mechanism of coagulation cascade reaction in the course of shock. The model of hemorrhagic shock was established. 40 SD rats were randomized into eight groups: pre-shock, and 1, 2, 4, 6, 8, 12 and 24 hours after shock, and the levels of plasma FVIII, vWF, TF, D-dimer, FIB, APTT and PT were detected respectively. The result showed that APTT and PT were gradually prolonged, which were significant within 4-6 hour after shock (P < 0.05). APTT and PT were 59.7 seconds and 30.2 seconds respectively. The level of plasma D-dimer markedly increased, and peaked at 8 hour after shock. The level of fibrinogen, TF, vWF and FVIIIa increased in the initial stage of shock. With the development of shock, fibrinogen markedly reduced from 2nd hour (P < 0.05) and dropped to the minimum at 7 hours after shock. Plasma TF, vWF, FVIII significantly decreased after 6 hours and 8 hours (P < 0.001). The ratios of the consumed coagulation factors: FVIII of (86.1 +/- 1.8)%, fibrinogen of (89.6 +/- 0.6)%, vWF (55 +/- 1.4)%, TF (62 +/- 2.5)%. Thus, coagulation factor I (fibrinogen) and FVIII were preferentially consumed. The extrinsic coagulation pathway was dominantly activated, whereas the intrinsic coagulation pathway played a less important role. Fibrinogen and D-dimer might be valuable for the prognosis of patients suffered from shock. It is concluded that hemorrhagic shock trigger the coagulation cascade reaction, and the coagulation factors are greatly consumed. Unbalance of coagulation system plays an important role in the progress of shock.